In recent years, a network management system (hereinafter referred to as NMS) for controlling a plurality of devices to be controlled, which are connected via a network, has been developed and used.
Various methods that enables further advanced control by such a NMS have been proposed (see Patent JP-A-2002-171289 and JP-A-2006-338417, for example). Patent Document 1 discloses a method for controlling all devices with one policy even though the network operation methods thereof that are intended to achieve the same function vary with vendors. Patent Document 2 discloses a proxy apparatus that performs a relaying operation so as to allow a SNMP (simple network management protocol) management apparatus to manage non-SNMP equipment easily. Such a NMS, however, does not have a mechanism for detecting automatically a device to be controlled.